How to Operate the Pipette Correctly?

Correct operation and skillful use of a pipette are crucial for obtaining accurate and reproducible results in laboratory work. Here are step-by-step guidelines for the correct operation of a pipette:

Before Using the Pipette

  1. Select the Right Pipette:
    • Choose the appropriate pipette based on the volume range you need to measure. Pipettes come in various sizes, such as micropipettes for microliter volumes and larger pipettes for milliliter volumes.
  2. Check Pipette Calibration:
    • Ensure that the pipette is regularly calibrated. If it has not been calibrated recently, or if it has been dropped or mishandled, it should be recalibrated before use.
  3. Select the Correct Pipette Tips:
    • Choose pipette tips that are compatible with the pipette model and the volume being pipetted. Ensure that the tips are free of contaminants.
  4. Inspect the Pipette:
    • Check the pipette for any visible damage, such as cracks or contamination. Ensure that the plunger operates smoothly.

Pipetting Procedure

  1. Adjust the Volume:
    • Set the desired volume on the pipette using the volume adjustment dial or digital display. Be sure to set the volume within the pipette’s specified range.
  2. Attach the Pipette Tip:
    • Attach a clean and properly sized pipette tip to the pipette nozzle. Ensure that the tip is securely attached to prevent leaks or inaccuracies.
  3. Pre-Rinse the Pipette Tip (Optional):
    • Some protocols recommend pre-rinsing the pipette tip with the liquid being pipetted to minimize volume errors, especially when working with viscous solutions.
  4. Aspirate the Liquid:
    • Immerse the tip into the liquid to be pipetted and slowly depress the plunger to the first stop. Hold the plunger at this position to allow the liquid to be drawn into the tip.
  5. Dispense the Liquid:
    • Position the pipette tip at the desired dispensing location and slowly release the plunger. Ensure that the liquid is dispensed smoothly without any sudden jerks.
  6. Touch-Off Technique (Optional):
    • For micropipettes, use the touch-off technique by lightly touching the tip against the side of the receiving vessel to remove any remaining liquid on the tip.
  7. Eject the Tip:
    • Eject the used pipette tip into a designated waste container. Ensure that the tip is properly discarded to prevent contamination.
  8. Rinse the Pipette (Optional):
    • Some protocols may require rinsing the pipette with a compatible solution, especially when changing between different liquids.
  9. Repeat as Needed:
    • Repeat the pipetting steps as necessary for the desired number of samples or replicates.

After Pipetting

  1. Store the Pipette Properly:
    • Store the pipette in an upright position, preferably in a designated pipette stand. This helps prevent contamination and damage.
  2. Clean the Pipette (As Needed):
    • Regularly clean the exterior surfaces of the pipette with a mild detergent or alcohol solution. Follow the manufacturer’s guidelines for cleaning.
  3. Check Calibration (Regularly):
    • Schedule regular calibration checks for the pipette to ensure ongoing accuracy. Follow the recommended calibration frequency.

By following these steps and incorporating good pipetting practices, users can minimize errors and achieve reliable and precise results in their laboratory work. It’s important to note that pipetting skills improve with practice, and users should pay attention to proper technique and ergonomic considerations.

Use and maintenance of pipettes

Set the capacity: When setting the required capacity, adjust it to 1/4 turn larger than the set capacity value, and then adjust to the set value. This can eliminate mechanical clearance and make the set value accurate. First, turn the capacity knob more than 1/4 turn of the target capacity value and then down to the set value.

Correct operation of aspiration

1. Connect the appropriate nozzles;
2. Press the control button to the file;
3. The pipette nozzle vertically into the liquid surface 1-6mm (depending on the size of the pipette);
A pipette of 0.1-10 ul capacity enters the liquid surface 1-2 mm;
2-200ul capacity pipette into the liquid surface 2-3mm;
1-5ml capacity pipette into the liquid surface 3 -6mm.
Note: To ensure accurate measurement, the nozzle can be pre-washed 3 times, that is, the liquid is repeatedly drained 3 times.
4. Slowly slide the control button back into place;
5. The pipettes can be slightly waiting for 1-3 seconds before moving out (depending on the size of the pipette);
Pause for 1 second below 1000ul;
5-10ml pause for 2-3 seconds.
6. Slowly remove the nozzle to ensure that there is no liquid on the outer wall of the nozzle.

Drain operation

(1) The nozzle is pressed against the inner wall of the capacity at an angle;
(2) Slowly press the control button to the file and wait for about 1-3 seconds;
(3) During the process of pressing the control button to the second gear, the suction nozzle drains the remaining liquid;
(4) Slow release control button;
(5) Press the ejection button to project the nozzle.